Obesity for donor is also related to CD4+ T cell–mediated aGVHD of recipients by controlling the differentiation of CD4+IL-2+, CD4+IFN-γ+ and CD4+TNF-α+ and Th17 cells (Figure 5D-5F, 6D). The gene discussed is TNF; the disease is obesity due to melanocortin 4 receptor deficiency.